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Resonance

In physics, resonance describes the phenomena of amplification that occurs when the frequency of a periodically applied force is in harmonic proportion to a natural frequency of the system on which it acts. When an oscillating force is applied at a resonant frequency of a dynamical system, the system will oscillate at a higher amplitude than when the same force is applied at other, non-resonant frequencies. Frequencies at which the response amplitude is a relative maximum are known as resonant frequencies or resonance frequencies of the system. Small periodic forces that are near a resonant frequency of the system have the ability to produce large amplitude oscillations in the system due to the storage of vibrational energy. Resonance phenomena occur with all types of vibrations or waves: there is mechanical resonance, acoustic resonance, electromagnetic resonance, nuclear magnetic resonance, electron spin resonance and resonance of quantum wave functions. Resonant systems can be used to generate vibrations of a specific frequency, or pick out specific frequencies from a complex vibration containing many frequencies.

The term resonance originated from the field of acoustics the sympathetic resonance observed in musical instruments, e.g. when one string starts to vibrate and produce sound after a different one is struck. Another example, electrical resonance, occurs in a circuit with capacitors and inductors because the collapsing magnetic field of the inductor generates an electric current in its windings that charges the capacitor, the discharging capacitor provides an electric current that builds the magnetic field in the inductor. Once the circuit is charged, the oscillation is self-sustaining, there is no external periodic driving action; this is analogous to a mechanical pendulum, where mechanical energy is converted back and forth between kinetic and potential, both systems are forms of simple harmonic oscillators. Resonance occurs when a system is able to store and transfer energy between two or more different storage modes. However, there are some losses from cycle to cycle, called damping; when damping is small, the resonant frequency is equal to the natural frequency of the system, a frequency of unforced vibrations.

Some systems have multiple, resonant frequencies. A familiar example is a playground swing. Pushing a person in a swing in time with the natural interval of the swing makes the swing go higher and higher, while attempts to push the swing at a faster or slower tempo produce smaller arcs; this is because the energy the swing absorbs is maximized when the pushes match the swing's natural oscillations. Resonance occurs in nature, is exploited in many manmade devices, it is the mechanism by which all sinusoidal waves and vibrations are generated. Many sounds we hear, such as when hard objects of metal, glass, or wood are struck, are caused by brief resonant vibrations in the object. Light and other short wavelength electromagnetic radiation is produced by resonance on an atomic scale, such as electrons in atoms. Other examples of resonance: Timekeeping mechanisms of modern clocks and watches, e.g. the balance wheel in a mechanical watch and the quartz crystal in a quartz watch Tidal resonance of the Bay of Fundy Acoustic resonances of musical instruments and the human vocal tract Shattering of a crystal wineglass when exposed to a musical tone of the right pitch Friction idiophones, such as making a glass object vibrate by rubbing around its rim with a fingertip Electrical resonance of tuned circuits in radios and TVs that allow radio frequencies to be selectively received Creation of coherent light by optical resonance in a laser cavity Orbital resonance as exemplified by some moons of the solar system's gas giants Material resonances in atomic scale are the basis of several spectroscopic techniques that are used in condensed matter physics Electron spin resonance Mössbauer effect Nuclear magnetic resonance The visible, rhythmic twisting that resulted in the 1940 collapse of "Galloping Gertie", the original Tacoma Narrows Bridge, is mistakenly characterized as an example of resonance phenomenon in certain textbooks.

The catastrophic vibrations that destroyed the bridge were not due to simple mechanical resonance, but to a more complicated interaction between the bridge and the winds passing through it—a phenomenon known as aeroelastic flutter, a kind of "self-sustaining vibration" as referred to in the nonlinear theory of vibrations. Robert H. Scanlan, father of bridge aerodynamics, has written an article about this misunderstanding; the rocket engines for the International Space Station are controlled by an autopilot. Ordinarily, uploaded parameters for controlling the engine control system for the Zvezda module make the rocket engines boost the International Space Station to a higher orbit; the rocket engines are hinge-mounted, ordinarily the crew doesn't notice the operation. On January 14, 2009, the uploaded parameters made the autopilot swing the rocket engines in larger and larger oscillations, at a frequency of 0.5 Hz. These oscillations were captured on video, lasted for 142 seconds. Mechanical resonance is the tendency of a mechanical system to absorb more energy when the frequency of its oscillations matches the system's natural frequency of vibration than it does at other frequencies.

It may cause violent swaying motions and catastrophic failure in improperly constructed structures including bridges, bui

Halgurd Mulla Mohammed

Halgurd Mulla Mohammed Taher Zebari is an Iraqi football player of Kurdish ethnicity who plays as a Left Winger for Brayati FC in Iraq. His older brother Hawar Mulla Mohammed is a retired Iraqi national team player and former teammates at club level. Born in Mosul in March 1978, he started his playing career with local club Sulaymaniyah FC in 2004. With his brother an integral part of the Iraqi Olympic side and national senior team, Halkard thrived at club level, spending his first two years establishing his place as one of the nation's burgeoning stars, he was first thrust into the international arena in the 2006 AFC Youth Championship, when he played in all four of Iraq's matches and was on target in the 2-2 draw against Saudi Arabia. After going on to feature in Iraq's failed qualifying campaign for the Olympic Football Tournament Beijing 2008, Mohammed made his senior debut in a friendly 1-1 against Jordan. Inspired by Hawar's success, he has worked hard to emulate his brother's achievements.

Now, with the FIFA Confederation Cup South Africa 2009 beckoning, the Iraqi fans will expect big things from the Mohammed brothers as they come together for the first time on the global stage. Halgurd was part of the Iraqi squad at the AFC Youth Championship 2006, he played four games and scored one goal at the 2-2 draw with Saudi Arabia. Halgurd was part with Iraq Olympic team in the Football at the 2008 Summer Olympics - Men's qualification campaign, he played several matches and helped Iraq to reach the final qualification stages. In 2007 Halgurd made his debut in a friendly match against Jordan and the match ended 1-1. In 2008 Halgurd took part in the 2008 VIVA World Cup with Iraqi Kurdistan and scored Iraqi Kurdistan's 2nd goal against Sapmi football team in the first match of the tournament, the match ended 2-2. In the second match against Provence, where Kurdistan won 3-0, Halgurd scored a brace. Kurdistan went on to win the VIVA World Cup for the first time in their history, beating North Cyprus 2-1, with Halgurd scoring the first goal of the match by a calm finish from the penalty spot.

Erbil SC Iraqi Premier League Winner: 2011-2012 Runner Up: 2010-2011, 2012-2013, 2013-2014 AFC Cup Runner Up:2012,2014Al Quwa Al Jawiya AFC Cup Winner: 2016 Halgurd Mulla Mohammed at National-Football-Teams.com Profile on Goalzz.com Official Forum

Rika Zaraï

Rika Zaraï is an Israeli singer and writer. Rika Gozman was born in Jerusalem. In the 1950s, the Israeli writer, Aharon Megged, wrote a musical for the IDF Central Command entertainment troupe about five soldiers falling in love with five country girls. In 1956, it was produced commercially by the Ohel theater starring Rika Zarai; the music was written by her husband Yochanan Zarai, with melodies by Naomi Shemer. In 1969, Zarai rose to fame with her songs Casatschok and Alors je chante, the French version of Vivo Cantando, she went on to have a successful career in Europe, where she popularized Israeli classic songs such as Hava Nagila, Yerushalayim shel zahav and Hallelujah. Zarai sings in Hebrew, French, Italian and German, she visits Israel periodically. According to a report in the Israeli newspaper Yediot Ahronoth in 2008, she suffered a stroke which paralyzed the left side of her body. Ma médecine naturelle, Michel Lafon, 1985 47 recettes de plantes, Mangina, 1986 Soins et beauté par l'argile et les plantes, Mangina, 1987 Mes secrets naturels pour guérir et réussir, J-C Lattès, 1988 Ces émotions qui guérissent, Michel Lafon, 1995 Le Code secret de votre personnalité, Michel Lafon, 1996 L'espérance a toujours raison, Michel Lafon, 2006 Music of Israel Culture of Israel Rika Zaraï on IMDb

2020 People's National Movement Tobago leadership election

The 2020 Tobago Council of the People's National Movement election were held on January 19, 2020. For the first time, a one member, one vote voting system was adopted for all 17 positions contested; the winner, Tracy Davidson-Celestine, the first female political leader for the party, went on to contest the Chief Secretary position of the Tobago House of Assembly in the 2021 Tobago House of Assembly election. The announcement of the election was made on November 10, 2019 by Chief Secretary of the Tobago House of Assembly and Political leader of the Tobago Council of the People’s National Movement, Kelvin Charles while speaking at the PNM's 49th annual convention, Queen's Park Savannah, Port of Spain. A total of 45 candidates contested the 17 positions on the Executive of the Tobago Council, the winner are as follows: Roles in bold are held. 2021 Tobago House of Assembly election Tobago House of Assembly

United Nations Security Council Resolution 1647

United Nations Security Council Resolution 1647, adopted unanimously on 20 December 2005, after recalling all previous resolutions on the situations in Liberia and West Africa, the Council extended sanctions including an arms embargo, bans on the sale of diamonds and timber and restrictions on travel for certain officials. The Security Council began by welcoming the successful conduct of elections in Liberia, which it viewed as an important step towards the peace and stability of the country, it welcomed the commitment of Ellen Johnson-Sirleaf to rebuild Liberia to benefit the people. Meanwhile, the Council concluded that "insufficient progress" had been made with respect to meeting the conditions of resolutions 1521 and 1532, which imposed sanctions on Liberia. Acting under Chapter VII of the United Nations Charter, the Council extended the arms embargo and travel restrictions for a period of twelve months, restrictions on the sale of diamonds and timber for a period of six months; the measures would be reviewed at the request of the Liberian government.

The resolution welcomed the determination of President Ellen Johnson-Sirleaf to meet the criteria required and encouraged the new government of the country to engage in forestry reform and management of diamond resources. Furthermore, it welcomed assistance provided to the Liberian government by the United Nations Mission in Liberia. An expert panel monitoring the implementation of sanctions against the country had its mandate extended until 21 June 2006. List of United Nations Security Council Resolutions 1601 to 1700 Second Liberian Civil War Works related to United Nations Security Council Resolution 1647 at Wikisource Text of the Resolution at undocs.org

Skeaikit

Skeaikit is an album by the Finnish folk music group Angelin tytöt, released in 1995 in Finland. The musical tracks consist of traditional Sámi yoiking mixed with electronic music in some of the songs; the album was recorded in the spring of 1995 with Art Without Brains Mobile in Kausala. "Bonkit go johtit" – 2:18 "Mouhtačalmmit" – 3:12 "Nieida" – 1:10 "Guoktelogiovcci" – 1:49 "Junná" – 5:10 "Báhka beaivi" – 1:46 "Silbana Elle Biehtár" – 1:04 "Márrat" – 3:45 "Giđđa beaivváš" – 5:45 "Džááš" – 0:21 "Vuoi daid ruđaid" – 2:30 "Dolla" – 4:21 "Julius Ánde" – 1:30 "Guldnasaš" – 7:02